反应详情

After an aqueous solution (40 ml) of sodium chlorite (6.0 g, 66.3 mmol) and sodium dihydrogenphosphate monohydrate (6.0 g, 43.5 mmol) was added dropwise to a solution of 2-hydroxy-6-methyl-3-(trifluoromethyl)benzaldehyde (4.65 g, 22.8 mmol) obtained in Example (28-2) in a mixture of tert-butyl alcohol (90 ml), 1,4-dioxane (30 ml) and 2-methyl-2-butene (30 ml), the mixture was stirred at room temperature for 1 hour. After the reaction mixture was cooled with ice and a 5% aqueous sodium thiosulfate solution was added thereto, the mixture was poured into 0.5N hydrochloric acid and extracted with ethyl acetate (twice). The organic layer was successively washed with water and a saturated aqueous NaCl solution and dried with anhydrous sodium sulfate. The residue obtained by removing the solvent under reduced pressure was crystallized using ethyl acetate and n-hexane to give 2-hydroxy-6-methyl-3-(trifluoromethyl)benzoic acid as a colorless compound (4.21 g, yield: 84%).

1. temperatureAfter the reaction mixture was cooled with ice
2. extractionextracted with ethyl acetate (twice)
3. washThe organic layer was successively washed with water
4. dry with materiala saturated aqueous NaCl solution and dried with anhydrous sodium sulfate
5. customThe residue obtained
6. customby removing the solvent under reduced pressure
7. customwas crystallized